Magnetization transfer and spin lock MR imaging of patellar cartilage degeneration at 0.1 t

PURPOSE: To investigate magnetization transfer (MT) parameters and rotating frame relaxation time T1 rho in patellar cartilage at different levels of degeneration. MATERIAL AND METHODS: Thirty cadaveric patellae were examined at 0.1 T using the time-dependent saturation-transfer MT technique and the spin lock (SL) technique. In an SL experiment, nuclear spins are locked with a radiofrequency (RF) field, and the locked nuclear magnetization relaxes along the magnetic component of the locking RF field. The specimens were divided into three groups according to the level of cartilage degeneration. MT parameters and T1 rho were measured. RESULTS: The MT effect was greater in degenerated cartilage than in normal cartilage. T1 rho was longer in advanced cartilage degeneration than in intermediate cartilage degeneration. CONCLUSION: The results suggest that more studies are needed to fully establish the value of SL imaging in cartilage degeneration.